Abstract:
We have studied photoluminescence (PL) from SiO2 films co-
doped with (Er, Ge) deposited by magnetron sputtering of an
Er+Ge+SiO2 composite target in pure Ar ambient. Under
excitation of a 325 nm He-Cd laser line, blue emission bands
around 400 nm and near infrared bands around 800 nm have been
observed, which are attributed to Ge-related defects and Ge
nanoclusters (Ge-ncls), respectively. Strong Er3+ PL at 1.54 μm
was also observed from the films, while the Er PL intensity of a
control Er-doped SiO2 film (i.e., without Ge), is negligible under
the same excitation. All the PL intensities vary as functions of
thermal annealing temperatures. The results demonstrate that the
significant enhancement of Er PL in the (Er, Ge) co-doped SiO2
films are due to the incorporation of Ge. The roles of Ge-ncls and
Ge-related defects to the Er3+ excitation are discussed.
